1. Field of the Invention
This invention relates to the isolation, identification and use of natural products as anti-tumor agents. More particularly, the present invention relates to seven new annonaceous acetogenins from Annona muricata, muricin A, B, C, D, E, F, and G, and their use in treating patients having tumors, and even some with hepatoma cancer.
2. Description of Related Art
Many plants of the Annonaceae have been used in folk medicine and insecticides. Among the constituents of these materials, annonaceous acetogenins, known to have potent anticancer activities, are regarded as the major active principles. Annonaceous acetogenins, a rather new class of natural compounds only isolated from the Annonaceae, are usually C35-C37 fatty acid derivatives connecting a variable number of Tetrahydrofuran (THF) or Tetrahydropryan (THP) rings and lactone terminal moiety. So far, more than three hundred compounds, most of which were steric isomers, have been found and published, and their more biological activities, such as cytotoxic, antiparasitic, insecticide and immunosuppressive activities, have been further proved.
Annona muricata L. (Annonaceae) is a well-known tropical fruit tree named “sour sop” or “guanabana”, which is mainly distributed in the Americas and in Southeast Asia. Currently, there have been more than forty annonaceous acetogenins isolated from the stems, leaves and seeds of this plant up. In the previous study of annonaceous acetogenins from Annona muricata by Li's el al., three annonaceous acetogenins, muricatin A, muricatin B, and muricatin C, were found from the extract of the stem bark. In those annonaceous acetogenins, four known compounds, muricatetrocin A, muricatetrocin B, corossolin, and corossolone, show special selective cytotoxicities against hepatoma cell lines, Hep G2, and 2,2,15. These four compounds are discussed with seven newly discovered annonaceous acetogenins in the detailed description in cytotoxicities of curing hepatoma.